LiquaGen Replacement Water Filter for 4.5 x 10" Big Blue Water System | Chlorine & Bacteria Reduction | KDF 55 & UDF Carbon Media LiquaGen does not distribute or sell products to any 3rd party sellers on Amazon. This product is sold exclusively on LiquGens Amazon store. Other companies selling this product are counterfeits. Please make sure to purchase a genuine LiquaGen product for proper authenticity and warranty. KDF 55 Medium Designed specifically for removing or reducing chlorine and water-soluble heavy metals. It controls scale, bacteria and algae, even in hot water. The process medium  Drinking Water Treatment Units  Aesthetic Effects. This medium is also in compliance with Californias Health and Safety Code Section 166875 (or commonly know as AB1953) and Vermont Act 193. Carbon is used to change the taste and odor of the water. Fits Standard 10" Big Blue Housing for Whole House Filtration Applications